In the prior art, a manually tightened chuck generally comprises chuck body member, jaw, nut, front sleeve and rear sleeve. Chinese Patent CN 2322725 authorized on Jun. 9, 1999 discloses a manually tightened chuck, the chuck comprises chuck body member, jaw, nut, front sleeve and rear sleeve. Three jaws are placed respectively in three inclined bores distributed uniformly on the chuck body member. Between the nut and the jaw thread connection is adopted, the rear end of the nut is provided with a thrust bearing, and the rear end of the thrust bearing is provided with a blocking ring, and on the rear end of the chuck body member the rear sleeve is assembled. The nut is of duplex-half structure. The duplex-half structure is combined into a integral through a nut sleeve, between the nut sleeve and the nut is of stationary fit, a key connection is adopted for torque transmission between the front sleeve and the nut sleeve, an annular protruding is formed in the inner surface of the front end of front sleeve, the chuck body member at the position corresponding to the protruding is provided with a annular groove, the axial orientation of front sleeve is achieved by said protruding fitting with said groove. The disadvantages of the manually tightened chuck are:
Since a key connection is adopted between the front sleeve and the nut sleeve, the machining of both front and nut sleeves of the chuck is more complex, and the key connection causes radial gaps between the front sleeve and the nut sleeve, thereby larger radial jitter may be created in the front sleeve during operation of the chuck.